Well casing hanger



Jan. 7, 1969 5, w, PUTCH 3,420,308

WELL CASING HANGER Filed Aug. 16, 1967 Sheet Of 4 FIELI INVENTOR. SAMUELW. PUTCH BYE/MW ATTORNEYS Jan. 7, 1969 s. w. PUTCH 3,420,308

WELL CASING HANGER Filed Aug. 16, 1967 Sheet 2 of 4 F'IE .I=

INVENTOR. SAMUEL w. PUTCH BYJWW AT TORNE YS Jan. 7, 1969 s. w. PUTCH3,420,308

WELL CASING HANGER Filed Aug. 16, 1967 Sheet J of 4 F IB E INVENTOR.SAMUEL w. PUTCH BYJWM ATTORNEYS Jan. 7, 1969 s. w. PUTCH 3,420,308

WELL CASING HANGER Filed Aug. 16, 1967 Sheet 4 of 4 F'II3 E INVENTOR.SAMUEL w. Pu'rcH ATTORNEYS United States Patent Office Patented Jan. 7,1969 3,420,308 WELL CASING HANGER Samuel W. Putch, Harris County, Tex.,assignor to FMC Corporation, San Jose, Calif., a corporation of DelawareFiled Aug. 16, 1967, Ser. No. 661,039 US. Cl. 166-208 Int. Cl. E21b17/046 7 Claims ABSTRACT OF THE DISCLOSURE Background of the inventionThe field of art to which this invention pertains includes devices forsuspending pipe or casing in wells or shafts bored into the earth, andmore particularly to such devices for suspending an inner casing at apredetermined position inside an outer casing. More particularly, theinvention relates to devices commonly known as casing hangers, and tothose hangers which include an expansible and contractible elementadapted to expand into a predesignated section of the outer casing topreclude downward travel of the inner casing within the outer casing.

In the practice of drilling wells for the recovery of valuable fluidssuch as oil and gas, it is customary to line the well bore with a seriesof concentric pipes, called casing strings, suspended from the top ofthe well by a hanger device that fastens an inner casing to the nextadjacent outer casing. Where wells are drilled in off-shore locations,and particularly in deep water, it has been found desirable to supportthe several casing strings at the ocean floor to take advantage of theearths lateral and vertical support, rather than at the waters surfacewhich leaves the casing highly susceptible to damage or loss as a resultof surface storms, tidal fluctuations, strong currents, and sometimesjust the great weight itself of an extensive length of heavy pipe. Toovercome this problem, hangers that can be positioned at any desiredplace in an outer casing string have been developed to suspend the innercasing string at any level in the well, including at the ocean floor.

Although in general these hangers operate satisfactorily, many contain aplurality of spring-biased locking elements that are expanded into thelanding section of the outer casing to secure the inner casing to it,and these springs can break or otherwise fail to perform. Anotherproblem with hangers of this type is that they usually contain a numberof parts which are rather intricate and therefore expensive. Further,the more complex the hanger the greater chance there is for it tomalfunction, requiring a halt in well operations until the problem iscorrected. Applicants present invention is designed to overcome each ofthese problems, and in so doing provides a new type of hanger that hasfewer parts, is simpler to operate, and is less susceptible tomalfunction than prior devices for this purpose.

Summary of the invention Broadly considered, applicants inventioncomprises a hanger for connecting an inner pipe or casing to an outerconcentric pipe or casing at a pre-designated location to preventfurther downward movement of the inner casing in the outer casing, butpermit upward movement of the inner casing with respect to theoutercasing, and includes a tubular hanger body adapted for connectingto the upper end of the inner casing, a self-expandable hanger ringsurrounding the hanger body and retained on it by a system of upper andlower stops, and a shear ring and pin assembly that responds to theweight of the casing to allow the hanger body to lock the hanger ring inits expanded condition. The hanger cooperates with a hanger couplingthat can be positioned in the outer casing at any desired level, thehanger ring being resiliently retracted and having an outerconfiguration complementary to the inner configuration of the hangercoupling. Thus when the inner casing is lowered through the outer casingand the hanger ring comes into position opposite the hanger coupling,the ring automatically expands into the coupling without furthermanipulation. The shear ring and pin assembly retains the hanger ring inproper position on the hanger body while the hanger is being lowered inthe outer casing, and includes a shear ring circumscribing the hangerbody above the hanger ring, and a plurality of frangible shear pins thatreleasably secure the shear ring to the hanger body. The pins aresevered by the shear ring when the weight of the inner pipe is allowedto bear on it, thereby permitting the shear ring and the hanger ring tomove upwardly on the hanger body into a final locked position preventingfurther downward movement of the inner casing. However, from thisposition the inner casing can be moved upwardly, and in fact withdrawnfrom the outer casing, simply by lifting up on the hanger body, therebycausing the hanger ring to move back to its former position on the bodywhere it can contract as restrictions in the outer casing areencountered and allow the inner casing to continue its upward travel.Applicants casing hanger thus provides all of the desirable functionsand the advantages of the prior devices for this purpose without severalof the more aggravating disadvantages thereof.

Brief description of the drawings FIGURE 1 is a view in side elevation,and partially broken away, of the casing hanger of this invention,connected at its lower end to a string of well casing and at its upperend to a conventional running string.

FIGURE 2 is a view in section, taken along the line 22 of FIGURE 1,through the shear ring and the hanger body.

FIGURE 3 is a view in section, taken along the line 3-3 of FIGURE 1,through the hanger ring and the hanger body.

FIGURE 4 is a view in side elevation, and partially broken away, showingthe casing hanger of FIGURE 1 as it is being lowered in an outerconcentric casing string.

FIGURE 5 is a view in side elevation, and partially broken away, showingthe hanger after it has reached the hanger coupling in the outer casingstring of FIGURE 4.

FIGURE 6 is a view similar to FIGURE 5, but illustrating the hanger inits subsequent locked position in the hanger coupling.

Description of the preferred embodiments Referring now to the drawings,the casing hanger 10 of the present invention includes a tubular body12, a resiliently expandable and contractible hanger ring 14circumscribing the body 12, a shear ring 16 above the hanger ring 14 andcircumscribing the body 12, and a plurality of frangible shear pins 18that releasably hold the shear ring 16 in position on the body 12. Theupper portion 20 of the body 12 is provided with an internal set of acmethreads 22 for connecting the casing hanger to a running string (notshown) through a landing sub 24, this connection being fluid tight byvirtue of the seals 26. The lower portion 28 of the hanger body 12 isprovided with external threads 30 to facilitate joining the body 12through a coupling 32 to the upper end of a casing string 34.

The hanger body 12 has an inner cylindrical surface 36, an upper outercylindrical surface 38, and a lower outer cylindrical surface 40 oflesser diameter than the surface 38. In its preferred form, the innersurface 36 has an annular groove 42, and is relieved above the groove 42to form an upwardly-facing stop shoulder 44, the groove 42 and shoulder44 providing landing means for suspending another string of casinginside the hanger body 12 with another hanger of this type. It is to beunderstood that the inner surface 36 may be provided with otherconfigurations, or may have no grooves or shoulders, as desired.

The upper outer surface 38 of the hanger body 12 is provided with anupper stop shoulder 46 having an outer cylindrical surface 48 and adownwardly facing radial shoulder surface 50 for contacting the shearring 16 and preventing further downward movement of the body 12 therein,the shoulder 46 being separated into a plurality of segments by axiallyextending grooves 52 in the surface 38. Projecting outwardly from thehanger bodys lower outer surface 40 is a lower stop shoulder 54 forretaining the hanger ring 14 on the body 12, the shoulder 54 having anouter cylindrical surface 56, an upwardly facing, inverted generallyconical surface 58, and an inner, upwardly facing radial shouldersurface 60, the shoulder 54 likewise being divided into a plurality ofsegments by grooves 62.

Extending downwardly from the upper stop shoulder 46 is a cylindricallocking surface 64 that serves to look the hanger ring 14 in its fullyexpanded condition, and extending upwardly from the lower stop shoulder54 is another cylindrical surface 66. A radially-extending surface 68joins the two surfaces 64, 66, providing a stop 70 that prevents thehanger ring 14 from being accidentally forced upwardly on the hangerbody 12 as it is being lowered through the outer casing.

The hanger ring 14 has an inner cylindrical surface 72, an outercylindrical surface 74, and upper and lower annular end surfaces 76, 78,respectively.

The outer edges of the upper and lower ends of the ring 14 are beveledto provide camming surfaces 84, 86 for retracting the ring 14 when itencounters obstructions as the hanger 10 is moving through an outercasing. Extending outwardly from the upper end of the outer cylindricalsurface 74 is a downwardly facing annular radial shoulder surface '88that, in combination with the cylindrical surface 90, provides a stopshoulder 92 which cooperates with an upwardly facing surface 138 of thestop shoulder 94 (FIGS. '5 and 6) in a hanger coupling 96 to precludefurther downward movement of the hanger ring 14 in the coupling.

The lower portion of the hanger ring 14 has an outer cylindrical surface98 and a downwardly and outwardlyextending upper surface 100 that,together with the lower beveled surface 86, form an annular boss 102.The boss 102 prevents the hanger ring 14 from expanding into a groove orother relieved area in the outer casing until the ring is properlypositioned in the hanger coupling 96, as shown in FIGURE 5. The diameterof the cylindrical surface 98 is greater than that of the cylindricalsurface 90 of the shoulder 92, and as a result when the hanger 10 iswithin an outer casing 104 (FIGURE 4) only the surface 98 is in contactwith the outer casings inner surface 106.

The hanger ring 14 is split axially throughout its length,

and therefore has axially extending opposed surfaces 108, 110, as isperhaps best illustrated in FIGURE 3. The ring 14 also is divided into aplurality of rigid segments 14a, b, c, etc. (FIG. 3), by a plurality ofaxial slots 112, but has an annular web 114 that joins the severalsegments together. The web 114 is dimensioned to permit the ring 14 toexpand and contract as required for passing obstructions in the outercasing as well as for proper seating of the ring in the hanger coupling.

When in its rest position as illustrated in FIGURES 1, 2, 4 and 5, theshear ring 16 is mounted on the locking surface 64 of the hanger body 12immediately above the hanger ring 14 through frangible shear pins 18that preclude axial movement of the shear ring 16 on the body 12. Theshear ring 16 has upper and lower annular radiallyextending surfaces116, 118, respectively, the surface 118 functioning as a stop forpreventing the hanger ring 14 from moving toward the upper portion 20 ofthe hanger body 12. When the casing hanger 10 is fully set and locked,as shown in FIGURE 6, the surface 116 bears against the radial surface50 of the upper stop shoulder 46, so that the forces tending to move thehanger 10 and the inner pipe 34 further downwardly are transferredthrough the shear ring 16 to the hanger ring 14, and thence to thehanger coupling 96 in a secure, positive manner. As shown best in FIGURE2, the shear ring 16 is axially split at 120 and is provided with aplurality of inner axially extending slots 122, for imparting theresilient expandability and contractibility required to install the ringon the hanger body 12 by slipping it over the shoulder 46.

As illustrated in FIGURES 5 and 6, a hanger coupling 96 connected at thedesired level into the outer casing 104 provides a landing device forsuspending the inner casing 34 in the outer casing. The upper end of thehanger coupling 96 preferably has acme threads 124 to releasably join itto a landing sub 126 which, in turn, is threaded at its upper end intothe outer casing 104. The internal cylindrical surface 128 of the hangercoupling 96 has an annular groove 130 with an axially extendingcylindrical surface 132 and upper and lower inwardly diverging endsurfaces 134, 136, respectively. Above the groove 130 a radial surface138 extends outwardly from the cylindrical surface 128 to anothercylindrical surface 140.

Also, as shown in FIGURES 5 and 6, if it is desired to suspend the outercasing 104 in still another casing of larger diameter (not shown), thehanger coupling 96 may be provided with a stop shoulder 142, a shearring 144, and a hanger ring 146, all analogous to the correspondingelements of the hanger 10, i.e., the hanger coupling 96 may be shapedlike casing hanger 10, but of larger diameter. Of course, it should beunderstood that the hanger coupling 96 needs only an internalconfiguration that will cooperate with the hanger 10 and hold itsecurely, so that hanger couplings other than the type illustrated at 96are also within the scope of this invention.

As is apparent from the foregoing description, suspending a string ofinner casing in an outer casing with the hanger 10 involves merelylowering the hanger and the inner casing in the outer casing, i.e., norotation or other manipulation procedures are required. As explainedpreviously, while the hanger 10 and the inner casing 34 are beinglowered the cylindrical surface 98 of the hanger ring 14 remains againstthe inner surface 106 of the outer casing 104, as illustrated in FIGURE4, holding the hanger ring 14 sufficiently retracted to prevent itsshoulder 92 from contacting restrictions that might be present in theouter casing and stopping the downward travel of the inner casing andhanger. As the hanger 10 reaches the level illustrated in FIGURE 5, thehanger ring 14 expands into the coupling 96, the boss 102 entering thecoupling groove 130 and the stop shoulder 92 moving outwardly toward thecouplings inner cylindrical surface 140. When the hanger ring 14 isexpanded fully (FIGURE 5), its cylindrical surfaces 90, 98 bear againstthe couplings cylindrical surfaces 140, 132, respectively, its entireradial end surface 76 is beyond the couplings stop shoulder 70, and thesurface 88 of its stop shoulder 92 extends over the radial surface 138of the couplings stop shoulder 94.

The holding tension on the running string is then relaxed, transferringthe weight of the inner casing string 34 to the coupling 96 through theshear ring 16 and hanger ring 14. This shears the pins 18 and pulls thehanger body 12 downwardly within the shear ring 16 until the radialsurface 50 of the hanger body stop shoulder 46 comes to rest on theshear rings upper surface 116, as is illustrated in FIGURE 6.Simultaneously, the shoulder 70 and the locking surface 64 of the hangerbody 12 move down inside the hanger ring 14, preventing the ring 14 fromretracting and releasing its grip on the hanger coupling. Thus, in thecondition shown in FIGURE 6, the hanger is set and locked in thecoupling 96 to suspend the casing 34 from that point.

Although setting and locking the hanger 10 in the coupling 96 precludesfurther downward movement of the hanger and its attached inner casing34, one of the advantages of this invention is that the hanger and innercasing can be raised out of the coupling 96 and the outer casing simplyby lifting on the hanger body 12. As the body 12 moves upwardly and thefirst restriction is encountered by either of the hanger rings beveledsurfaces 84, 100, such as when the upper surface 134 of the hangercouplings groove 130 is encountered by the surface 100, the hanger ring14 is held by the restriction until the lower stop shoulder 54 contactsthe rings lower end surface 78. The ring 14 then continues upwardly Withthe body 12, and in doing so retracts inwardly in response to thecamming action of the beveled surface that is bearing against therestriction. In similar manner the beveled surfaces 84, 100 cam the ring14 past subsequent restrictions in the outer pipe. Thus neither rotationnor any other procedure except lifting is required to withdraw thehanger 10 from its coupling.

Once the inner pipe is hung (FIG. 6), the running string is rotated toback the landing sub 24 out of the hanger body 12, and then lifted fromthe well. Other well operations then can be conducted in theconventional manner, including lowering and setting another string ofeasing within the inner casing 34 by using the hanged body 12 with itsgroove 42 and stop shoulder 44 as the coupling. When it is desired toremove the inner casing 34, a running string with a landing sub islowered, rotated in the opposite direction to connect the sub to thehanger body 12, and then lifted back out, bringing the hanger 10 and theinner casing 34 with it.

The casing hanger 10 can be employed to suspend casing at any desiredlocation in the well merely by properly positioning the cooperatinghanger coupling 96. For example, this hanger is ideally suited foron-bottom suspension of the casing in an underwater well where there isadequate support so that the surface conductor, which extends from theocean floor to the surface of the water, does not have to bear theweight of the inner strings of casing and thus is not subjected to unduecompressive load. The hanger also serves unusually well for suspendingcasing strings in a telescoping manner, i.e., each string suspended fromthe bottom of its immediately adjacent outer string, thereby reducingcasing expense. Since no slips are used in this hanger, the attendantdisadvantages thereof, such as casing distortion, are avoided.Conventional cementing procedures can be carried out through thishanger, the slots 52 and 62 providing ample fluid bypasses.

Although the best mode contemplated for carrying out the presentinvention has been herein shown and described, it will be apparent thatmodification and variation may be made without departing from what isregarded to be the subject matter of the invention as set forth in theappended claims.

I claim:

1. A pipe hanger assembly for suspending an inner pipe within and froman outer pipe, comprising: an elongated tubular hanger body with upperand lower ends, said upper end adapted for releasable connection to awell tool and said lower end adapted for connection to a pipe, upperstop means extending outwardly from the outer surface of said hangerbody intermediate said ends, lower stop means extending outwardly fromthe outer surface of said hanger body intermediate said upper stop meansand said lower end, a resiliently expandable and contractible hangerlocking ring circumscribing said hanger body and axially slidablethereon between said upper and lower stop means, said ring adapted forself-movement from a contracted condition into an expanded condition topreclude downward movement of said hanger body in said outer pipe whilefacilitating upwand movement of said hanger body therein; locking meanson the outer surface of said hanger body intermediate said upper andlower stop means and adapted to lock said 'hanger locking ring in itsexpanded condition, and releasable stop means on the outer surface ofsaid hanger body intermediate said upper stop means and said lockingring for preventing said locking means from locking said locking ring insaid expanded condition.

2. The pipe hanger assembly of claim 1 wherein said hanger locking ringis split axially and is provided with a lower outwardly-extendingannular boss and an upper outwardly-extending annular locking shoulder.

3. The pipe hanger assembly of claim 2 wherein said annular boss has alarger outside diameter than said annular locking shoulder, forproviding a bearing surface for said locking ring with respect to saidouter pipe.

4. The pipe hanger assembly of claim 3 wherein said locking ring isdivided into a plurality of rigid axially extending segments by aplurality of axial slots.

5. The pipe hanger assembly of claim 4 wherein said locking meanscomprises a cylindrical locking surface extending from said upper stopmeans towards said lower stop means, and having a diameter sufiicient tohold said locking ring in expanded locking condition with respect tosaid outer pipe when said ring is circumscribing said surface.

6. The pipe hanger assembly of claim 5 wherein said releasable stopmeans comprises an annular shear ring circumscribing said lockingsurface and releasably secured thereto by frangible shear pins.

7. The pipe hanger assembly of claim 6 wherein said lower stop meansincludes an outer axially extending retainer flange for retaining saidlocking ring in position on said hanger body.

- References Cited UNITED STATES PATENTS 3,017,931 1/ 1962 Jackson et a1166-208 3,086,590 4/1963 Jackson et al 166--.6 3,227,218 l/l966 Fisheret a1 166-208 3,305,015 2/1967 Brown et al 166.6

JAMES A. LEPPINK, Primary Examiner.

US. Cl. X.R. 285-

